Acquired Fanconi Syndrome with Proximal Tubular Cytoplasmic Fibrillary Inclusions of λ Light Chain Restriction

作者：Yao, Ying; Wang, Su-Xia^*; Zhang, You-Kang; Wang, Yan; Liu, Li; Liu, Gang

来源：Internal Medicine, 2014, 53(2): 121-124.

DOI：10.2169/internalmedicine.53.0836

• Fanconi syndrome
• immunoglobulin light chains
• multiple myeloma

Light chain proximal tubulopathy is a rarely reported entity associated with plasma cell dyscrasia that classically manifests as acquired Fanconi syndrome and is characterized by the presence of kappa-restricted crystals in the proximal tubular cytoplasm. We herein present a case of multiple myeloma with Fanconi syndrome and acute kidney injury due to light chain proximal tubulopathy with light chain cast nephropathy. Prominent phagolysosomes and numerous irregularly shaped inclusions with a fibrillary matrix in the cytoplasm of the proximal tubules were identified on electron microscopy. A monotypic light chain of the lambda type was detected in the distal tubular casts, proximal tubular cytoplasmic lysosomes and fibrillary inclusions on immunofluorescence and immune electron microscopy. This case underscores the importance of conducting careful ultrastructural investigations and immunocytologic examinations of light chains for detecting and diagnosing light chain proximal tubulopathy.

• 出版日期2014
• 单位北京大学